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It is several years already I trying some Air Quality monitors. And I think it is time to post some of the results. So here it is. Overview of some Air Quality monitors tested so far.

For me perfect device is the one:

1. measure correctly
2. measure multiple parameters
3. display information locally
4. has a battery and can be used as a mobile tool
5. is an IoT device with Wi-Fi connectivity and mobile app
6. not cost a fortune
7. quiet

Some of the requirements are cannot (or at least not easy to) be met simultaneously. A lot of advanced sensors with Wi-Fi connectivity and good mobile application make the device expensive. Battery and battery charging circuits usually affect temperature and relative humidity measurements. Active airflow improves measurement speed and quality but makes devices noisy. So there is no single perfect device yet to cover all Air Quality Monitor use cases. That is why I choose some devices I like more by category.

IoT Air Quality Monitors

Best IoT Air Quality Monitor “award” goes to AWAIR 2

• ✔️Good design
• ✔️Local data display
• ✔️IoT device with a nice mobile application
• ✔️Good hardware design (airflow, antennas, etc.)
• ✔️ CO2, PM2.5, VOC, temperature, humidity
• ❌Not all sensors are perfect
• ❌No iPad application
• ❌No battery
• ❌Noise
• 170-200$

So as you can see above the device is not perfect. It is noisy, that is how good airflow and better measurement quality and speed achieved. Some Sensors are not the best in class, that is how the price is lower than 200$. For more details see AWAIR 2 Review.

IoT Alternatives

uHoo

✔️ quiet, more parameters (CO, O3, NO2), iPad app
❌ expensive (330$), cheaper sensors, no local display

AirVisual Pro (Node)

✔️ large display, outdoor data for PM2.5, battery, iPad app
❌ more expensive (280$), fewer parameters (no VOC)

Netatmo Smart Home Weather Station (Urban Weather)

✔️ quiet, weather station (external t/RH module), iPad app, 180$
❌ fewer parameters (no PM2.5, no VOC), poor CO2 sensor

Air Mentor 2s

✔️ quiet, more parameters (HCHO), iPad app
❌ Bluetooth or additional hub, single color status LED, 330$

Airthings Wave Plus

✔️ quiet, Radon sensor, work from 2xAA, iPad app, 200-270$
❌ fewer parameters (no PM2.5)

Portable Monitors

Best Portable Air Quality Monitor “award” goes to K6-D

• ✔️Several hours of battery life
• ✔️Good Sensors
• ✔️ CO2, PM2.5, VOC, temperature, humidity
• ✔️ Low price ~100$
• ❌Humidity measurements not perfect
• ❌No connectivity
• ❌Noise

Again, as it was with the best IoT device, this one is not perfect. It is noisy, it has no Wi-Fi/Bluetooth/etc, humidity measurements may show -10% RH on high humidity tests, but still, it is better than some others and good for the price.

Portable Alternatives

D9-H

✔️ additional HCHO Sensor
❌ less temperature/humidity accuracy, 110$

AirVisual Pro (Node)

✔️ less noisy, large display, outdoor data for PM2.5, battery, IoT
❌ more expensive (280$), fewer parameters (no VOC)

DM601A

✔️ large display
❌ wrong temperature and humidity, cheaper sensors, ~110$

HT-401

✔️ small
❌ CO2 only, ~124$ , battery sold separately, auto power-off

HT-501

✔️ PC app for data logging
❌ wrong temperature and humidity, no VOC, no PM2.5 ~80$

Airthings wave plus

✔️ quiet, Radon sensor, months of work from 2xAA
❌ fewer parameters (no PM2.5), 200-270$, single LED local status display.

Other Air Quality Monitors

Best in Most Trusted device category is Green Day AZ7788

• ✔️Correct measurements
• ✔️Old, but a good type of sensors
• ✔️ Relay output
• ❌Only C02
• ❌No connectivity
• ❌No battery
• ~110$

Old school device with separate analog temperature and humidity sensors, Old model of CO2 sensor. No other air quality sensors present. Need to be always plugged. But still one of the best in measurement quality.

Hti HT-401 is the most portable CO2 meter I have. It is small and simple. It is only 75 mm in diameter and 25 mm in depth. Weight is 62 g. That is including 14250 (1/2AA) 300 mAh battery. Its only button is power. It count 30 seconds before actually show the CO2 level. And it automatically power off after 30 minutes.

Four-digits LED display only shows CO2 level and 3 emoticons 🙂<600ppm 😐600-1200ppm 🙁>1200. That is it. No settings for emoticons limits. No setting for the power-off timer. Not display temperature and humidity, nor time and date. Just one sensor inside and that is well known SenseAir S8 LP. That provides correct readings. Changing the environments not impact accuracy. The device is relatively cheap (I bought it for about 75$ without battery on Aliexpress)